Heat-transfer apparatus



c. E. HAWKE 7 HEAT TRANSFER APPARATUS Filed Feb. 17, 1923 bi "m Patented Jan. 27, 1925.

UNITED STATES PATENT OFFICE.

CLARENCE E. HAWKE, G33 lvIETUCHE-N, NEW/V JERSEY, ASSIGNOR TO THE CARBORUN- DUlVl'. COMPANY, OF NIAGARA FALLS, NEVJ YORK, A CORPORATION OF PENNSYL- VANIA.

HEAT-TRANSFER APPARATUS.

Application filed February 1'7, 1923. Serial No. 619,626.

Be it known that I, CLARENCE E. HAWKE,

a citizen of the United States, residing at Metuchen, county of Middlesex, and State of 1; New Jersey, have invented a new and useful 5 Improvement in Heat-Transfer Apparatus, of which the following is a full, clear, and exact description.

This invention relates to heat transfer transfer apparatus, and is particularly 1 adapted for use in constructions where fuel is burned inside a combustion space or passage, the walls of which transfer the heat of combustion to a surrounding space.

Heretofore it has been very hard, if not 1 impossible, to maintain such constructions in continuous working order, because the flames from the burner generally tend to impinge on one side of the combustion passage. i This results in unequal expansion and-contraction, eventuating in a cracking of the passage. This is particularly true where refractory tubes are employed.

My invention provides an inner sleeve or lining for protecting the faces of the heat transfer walls, thereby preventing a direct impingement of the flame and highly heated gases and eliminating the ditficultles occasioned thereby. The protecting sleeve is preferably constructed of a material of high thermal conductivity, such as silicon carbide,

and should also be free to expand and contract independent of the tube or passage proper.

My invention further provides ready means for the removal and replacement of the protecting sleeve when occasion demands.

In the accompanying drawings, illustrating the present preferred embodiment of my invention:

Figure l is a sectional view illustrating my invention as applied to a furnace,

Figure 2 is a section on the line 11-11 of Figure 1, and

Figure 3 is a perspective view of a detail of my invention.

In the illustrated embodiment of my invention a combustion chamber or passage 2 projects through the wall 3 of a furnace into the working chamber or interior 4 whlch 1s to be heated by conduction of heat through the walls of the passage 2. It will be understood that a lurality of such passages may be employed according to the requirements of any particular installation. The passage 2 includes a section 5 which is of refractory material, such as silicon carbide, and is preferably circular in cross section. Further units or tubes 6 may be supplied to extend the passage 2 to any desired length. The sections 5 and 6 are joined by an insert 7 which is cemented into the section 5. The

bell mouth 8 of the section 6 is then placed over the projecting end of the insert 7, and the sections 5 and 6 are cemented together to secure a gas tight joint. The other end of the section 5 is inserted a short distance into the furnace wall 8 and is cemented therein, as shown at 9. Another section 10,

whose length is substantially the thickness of the wall, is introduced into the bell mouth 11 of the section 5 to continue the passage to the outside of the furnace. rib 12 is provided on the outside of the section 10, and this annular rib has beveled edges adapted to co-operate with the outer end of the bell mouth 11 to form a tight An annular 7 joint. The joint is, however, cemented as shown at 13 to obviate any possibility of leakage. A burner 14 of any type, depend ing on the fuel employed, is placed outside the furnace and directed along the axis of the passage 2.

I have found, however, that in practice the flame does not coincide with theaxis, and in any event spreads considerably in the passage 2, with the result that there is generally a more or less concentrated impingement on one portion of the passage, tending toward cracking and rapid destruction of the apparatus. To overcome this, I provide a lining 15 for the section 5. This lining is tapered at the end adjacent the burner 14 to provide a smooth passage for the gases with no abrupt changes in cross section, and the lining 15 at its further end is inset in the insert 7 for the same purpose.

The lining 15 is constructed of a material W of high thermal conductivity, such as silicon The provision of the separate .sion requires.

because it reduces the temperature of the first. section 5, and tends to equalize the temperature of all the sections of the passage 2.

Since there is a great temperature difference between the inside and outside of the furnace Wall, there has heretofore been a considerable tendency toward c facl-zing of a passage When extended through the wall. .ection it), Which continues the passage through the Wall While the Working section 5 is extended only, a short distance into the wall, localizessuch a cracking tendency in the section 10.. This section may be readily removed by breaking away the cement 13 as occa- Moreover, by breaking au a, the cementz 9, the passage '2 may be removed entire, as Will be apparent from the drawmgs.

While Iliave shown one en'tbodiment of my invention, it Willbe understood that it is, not; limited thereto, but may be embodied in other constructions Within the scope of the following claims.

I claim: laHeat transfer apparatus, comprising a heatingchamber,and a comlnistion chamberextending Within said'heating chamber andlhavingrefractory heat transfer walls. said, combustion chamber having a separable inner lining forat least a portion of its length, substantially as described.

2. Heat transfer apparatus, comprising a heatin chamber, and acombustion chamber extending Within said heating chamber andihaving refractory heat transfer walls,

said combustion chamber having a separable inner lining for atleast a portion of its length adjacent the end thereof where the fuel is; introduced, substantially as described.

3. Heat transfer. apparatus, comprising a heating chamber, and a combustion chamber cXtending Within saidheating chamber and having refractory heat transfer \YttllS, said combustion chamber having a. separable lining of refractory material for at least a portion of its length,substantially as described.

I l. Heattransfer apparatus, comprising a heating chamber, and a combustion chamber extending Within said heatin ehan'iber and'having refractory heat tra or walls. saidcombustion chamber having a sc 'iarable inner lining for at least a portion of its length, said lining being mounted within said combustion chamber in such manner a to permit it to expand and contract in dependently of the Walls of said combustion chamber,substantially as described.

Heat transfer apparatus, comprising a heating chamber, and a combustion chamber extending Within said heatingchamber and 7' having refractory heat transfer Walls, said combustion chamber having a separable inner lining of refractory material for at least a portion of its length, said lining being loosely supported Within said combustion chamber on a. bed of granular material, substantially as described.

6., Heat transfer apparatus, comprisin a heating chamber, and a combustionchain er extending within said heating chamber and having refractory heat transfer walls, said combustion chamber having a separable inner lining of refractory material for. at least a portion of its length, said lining being loosely supported within said combustion chamber on a bed of granular material of high thermal conductivity, substantially as described.

7. Heat transfer apparatus, comprisin r a heating chamber, and a COII'lbllStiOllClltllIl er extending Within said heating chamberand having refractory heat tf'ansfer Walls, said combustion chamber having a bodily removable loosely mounted lining of refractory material for a portion of its length, substantially as described.

8. Heat transfer apparatus, comprising a heating chamber, and a tubular combustion chamber extending within said heating chamber and having refractory'heat t 'ansfer Walls, said combustion chamber having, a bodily removable tubular inner lining of re fractory material for at least a portion of its length, substantially as described.

9. Heat transfer apparatus,comprising a heating chamber having an opening. throu h awall' thereof, a combustion chamber Wit 1 in said opening and projecting into said heating chamber and having refractory heat transfer ivalls, said combustion chamber having an opening in the end thereof within fuelan'd having a removable inner. lining for a portion of its length adjacent said fuel opening, substantially as described.

10. Heat transfer apparatus, comprising a heating chamber having an opening through a Wall-thereof, a combustion chamber with in said opening and projecting into said heating chamber and having refractory heat transfer walls, said combustion chamber having an opening in the end thereof Within said Wall opening for the introduction of fuel and having a ren'iovable inner" lining of refractory material for a portion of its length adjacent: said fuel opening, substantially as described.

11. Heat transfer apparatus, comprising a heating chamber having an opening through a Wall thereof, and a tubular combustion chamber extending Within saidopening and projecting into said chamber and having re- 0nd section having its inner end portion seated within the outer end portion of the first section, substantially as described.

12. Heat transfer apparatus, comprising a heating chamber having an opening through a Wall thereof, and a tubular combustion chamber extending Within said opening and projecting into said chamber and having refractory heat transfer Walls, said combustion chamber comprising a section projecting into said heating chamber and having its outer end portion sealed into said opening and a second section Within said opening, said second section having its inner end portion seated Within the outer end portion of the first section and a removable tubular lining of refractory material for said first section, said lining covering the joint between said sections, substantially as described.

In testimony whereof I have hereunto set my hand.

CLARENCE E. HAWKE. 

